java.lang.VerifyError：期望一个stackmap框架

Question

Is there a way to load a custom HttpServlet to GAE? I uploaded a project that included an HttpServlet in the .server package and added it to the web.xml...

<servlet>
   <servlet-name>testServlet</servlet-name>
   <servlet-class>gwtone.server.TestServlet</servlet-class>
</servlet>

<servlet-mapping>
   <servlet-name>testServlet</servlet-name>
   <url-pattern>/tester/greet</url-pattern>
</servlet-mapping>

Is there something else I am missing, or is it not possible?

--------EDIT--------

some things that appear when i init my server, which im not used to seeing...

Jan 22, 2012 4:23:44 AM com.google.apphosting.utils.jetty.JettyLogger info
INFO: Logging to JettyLogger(null) via com.google.apphosting.utils.jetty.JettyLogger
Jan 22, 2012 4:23:44 AM com.google.apphosting.utils.config.AppEngineWebXmlReader readAppEngineWebXml
INFO: Successfully processed E:\Program Files\eclipse-SDK-3.7.1-win32-x86_64\Workspace\gwtone\war\WEB-INF/appengine-web.xml
Jan 22, 2012 4:23:44 AM com.google.apphosting.utils.config.AbstractConfigXmlReader readConfigXml
INFO: Successfully processed E:\Program Files\eclipse-SDK-3.7.1-win32-x86_64\Workspace\gwtone\war\WEB-INF/web.xml
Jan 21, 2012 10:23:44 PM com.google.appengine.tools.development.DevAppServerImpl start
INFO: The server is running at http://localhost:8888/
Jan 21, 2012 10:23:44 PM com.google.appengine.tools.development.DevAppServerImpl start
INFO: The admin console is running at http://localhost:8888/_ah/admin

and here is what shows when it crashes..

WARNING: Error for /tester/greet
java.lang.VerifyError: Expecting a stackmap frame at branch target 14 in method gwtone.server.TestServlet.doGet(Ljavax/servlet/http/HttpServletRequest;Ljavax/servlet/http/HttpServletResponse;)V at offset 0
    at java.lang.Class.getDeclaredConstructors0(Native Method)
    at java.lang.Class.privateGetDeclaredConstructors(Unknown Source)
    at java.lang.Class.getConstructor0(Unknown Source)
    at java.lang.Class.newInstance0(Unknown Source)
    at java.lang.Class.newInstance(Unknown Source)
    at org.mortbay.jetty.servlet.Holder.newInstance(Holder.java:153)
    at org.mortbay.jetty.servlet.ServletHolder.initServlet(ServletHolder.java:428)
    at org.mortbay.jetty.servlet.ServletHolder.getServlet(ServletHolder.java:339)
    at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:487)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1166)
    at com.google.appengine.tools.development.HeaderVerificationFilter.doFilter(HeaderVerificationFilter.java:35)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.api.blobstore.dev.ServeBlobFilter.doFilter(ServeBlobFilter.java:60)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.apphosting.utils.servlet.TransactionCleanupFilter.doFilter(TransactionCleanupFilter.java:43)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.StaticFileFilter.doFilter(StaticFileFilter.java:122)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at com.google.appengine.tools.development.BackendServersFilter.doFilter(BackendServersFilter.java:97)
    at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1157)
    at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:388)
    at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
    at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
    at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:765)
    at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:418)
    at com.google.appengine.tools.development.DevAppEngineWebAppContext.handle(DevAppEngineWebAppContext.java:78)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at com.google.appengine.tools.development.JettyContainerService$ApiProxyHandler.handle(JettyContainerService.java:362)
    at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
    at org.mortbay.jetty.Server.handle(Server.java:326)
    at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
    at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:923)
    at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:547)
    at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:212)
    at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
    at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:409)
    at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)

EDIT #2

package gwtone.server;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class TestServlet extends HttpServlet {

public TestServlet(){}

@Override
public void doGet(HttpServletRequest req, HttpServletResponse resp) 
        throws ServletException, IOException {
    System.out.println("0");
    try {
        System.out.println("1");
        resp.getWriter().println("IT WORKED");
        resp.getWriter().flush();
        System.out.println("2");
    } catch (IOException e) {
        e.printStackTrace();
    }
    System.out.println("3");
}
}

Answer 1

As BalusC pointed out, one solution to the problem is to just use JDK6.

Another solution, if you want to stay with JDK7, would be to use " -XX:-UseSplitVerifier " as an argument for the VM. Go to

Window → Preferences → Java → Installed JREs → Edit... → Default VM arguments

and add it there.

Answer 2

GAE uses Java 1.6, but you've compiled the code with Java 1.7. You need to recompile with Java 1.6. As per the comments, you're using Eclipse; you can set the Java compiler level in Java > Compiler section of project's properties.

Answer 3

Using -XX:-UseSplitVerifier is a temporary solution. Now java uses the previous version of the bytecode verifier which tolerates this bad or missing stackmap frames. Java8 doesnt support this option.

Answer 4

I could solve this issue by setting Eclipse Mars / Project properties / Java compiler :

• Compiler compliance level to 1.7 (as I don't have 1.6 anymore)
• Generated .class files compatibility : 1.6
• Source compatibility : 1.6

as I didn't have 1.7 specific code :-)

Server Ubuntu + Tomcat 7.0.52 on JVM 1.7.0_85-b01 Dev Eclipse Mars on JDK 7u55